Dopamine transporter (DAT) is a very reliable dopaminergic neuronal marker. Reduction in DAT density detected by I123 SPECT DaTscanTM in the dopaminergic neuron terminal striatum was reported in one small size study consisting of eight SCA6 patients in Korea. There was also a PET study using different radioligand for DAT in a small group of SCA6 patients in Germany, which found sub-clinical change in DAT density in some patients with SCA6.